Shock damping device



Jan. 3, 1933.

F. H.. ROYCE sHQoK DAMPING DEVICE Filed My 24, 1950 Jan. 3, i:` H, ROYCE l I SHOCK DAMPING DEVICE A Filed May 24, 1930 2 Sheets-Sheet 2 Patented Jan, 3, 1933 lJNl-rizo STATES 1,833,33sifA PAT-ENl'rfOFFICE FREDERICK HENRY ROYCE, or ELMSTEAD, WESTy wrrTjEnING, NEAR oHIoHEsTEa ENGLAND, AssIGNoa To. ROLLS .noYcE LIMITED, or DERBY, ENGLAND snoei:v DAMPING :oEvIcE y application med may 24, 1930, serial No. 455,334, man Gret-Britainjnay 29,1929.

This invention has reference to shock damper-s and is'mainly useful where the conditions vary, as they doin the case of shock dampers. fitted to motor cars, owing to varia ations in the quality of the road and/or in the speedof the vcar and/or the load carried.

A shock damper adjusted to function at its bestv ehciency under one set `of conditions does not function to the same eiiciency under 1o other conditions.

1 Accordingly shock dampers have been made adjustable and in the case of hydraulic shock dampers-where the release or escape is controlled bya valve opening against the reaction of a coiled metal spring, proposals haveV been made to adjust the tension of the spring .by moving its seat.

. This invention is an improved method of adjustingA hydraulic shock dampers and con- 2`0 sistsI of providing that one or more of the valves which control the release or escape shall open against the reaction -oan air spring' or air springs, in addition to, or in substitution for the usual coil spring, and providingmeans whereby the pressure off the air'constituting such airspring can be increased or diminished; v Y

In one form of this invention, the pathway of. the oil or other liquid from the, compression chamber of the shock damper is controlled by a one way mushroom valve. Such valve is loaded' as follows. A'coil spring is provided withone end seated on a metal plate seated against the head of the valve and the other ,onv a part of the casing of the shock damper immediately above the head of the valve or other suitable seating. Such spring may be arranged to-be of such strengthas to give the minimum shock dampingV eii'ect 40 required,` Around such spring is formed an airtight chamber consisting of a cylindrical box with corrugated sides so as to be eX- pandible and compressibl-e concertina fashion. one end being fix-ed and sealed by the said metal plate seated against the valve head, and the other lixed to and sealed by the casing of the shock damper around the seating ofV the spring remote from the valve or some other suitable base. An air pipe leads into such chamber at a point remote from the Vof' this invention is diagrammaticall'y illusvalve and gives access to the source of air. Then the valve lifts from its seating it compresses both the coil spring and the air in the airtight chamber, and accordingly, as the pressureof' the air in the latter is varied theresistance of the valve is increased or diminished.` Such air pressure may be varied, by means of the said pipe. Y v l A small by`pass may be provided whereby ,Y some portion ofthe oil inthe compression 6o chamber 'ofv the shock damper and any air which vmay collecttherein may escape without passing'th'roughthe` valve VIn the accompanying drawings an example trated.V `Figure l isa vertical sectiononthe lineV l-l of Figure '5. Figure 2y is across section on the line 2;-'2 of Figure l. vFigure 3Y is averticalsection on the line 3 3 of Figure- 5. Figure 4; is-a sectional plan View of 'Figure 2 on the line l--t of Figure 2 and Figure 5 is a` general plan view. Figs. y6, 7 8 illustrate inv section means for compressing the air. Y f al is a main part of the apparatus, al and a.11 are end parts spigotted to the mainpart a and secured thereto by studs and nuts. VThe main parta has an upstanding part a2 and the end f part al an upstanding part a3. at isa cover secured to 'the upstanding part a2 by studs 80 and nuts. cf is a coverover the part a3 secured thereto by screws (16' and having a T shaped upstanding part a7 on top thereof with two communicating conduits at right angles yto each other@8 and a? formed therein, 85 a web am and a union al? formed on the end of the conduit asto receive the pipe hereinafter described.` TheV ends of the conduits a9 communicate by vertical holes w13 to the inside of the cover( The part a ,with the end parts a1 and 0:11 comprises a cylindrical 'chamber c, an elongated chamber a and a reservoir or tank L16 extending down the side of the cylindrical chamber and merging into a circular part a underneath the cylindrical chamber, the elongated chamber a opensinto the reservoir am. Oil is admitted tothe apparatus through the opening al?. bis a double ended hollow piston slideable in the cylindrical chamber a actuated bythe lever 100 b1 through the shaft b2 which has a square part b3, the lever b4 clamped on such square flange c thus forming two chambers c2 and c3. Y

From the bottom of each of such chambersl are drilled two two-diameter holes c4 and c5.i

In each of thesev isa mushroom valve c6 and 07 seating on chamfers formed o-n tlie topl of the larger diameter portion of the holes c4 and c5 with stems fitting and sliding in the smaller diameter part of such holes. cs and 09 are metalplates held down on the head of the valves c and c7 by two springs @1 0 and' c reacting at one end on such plate and at the other end on the cover plate a5. 01.2 and 013 are two cylinders with corrugated sides sealed'at one end by the said metal plates es and o9 and at the other by the cover plate a5. d is a conduit drilled through the main part ofthe main casting aand into the end parts a1 and an connected with the circularpart a ofthe reservoir and with. each end of thc chamber al* via conduits d1 and d2; d3: are one-way ball valves admitting liquid into the ends of the chamber L14 and d* is a conduit drilled through the main part a and into the end parts al and a opening! at one end into the end of the chamber a14r at the left side of the piston and at the otherend into a conduit Z5 which is connected via the conduit fl to the. space c2 above the mushroomvalve c6 and also connected directly to the hole 05 be- J low the head of the mushroom valve c7. e' is a pipe connected by a nut e1 to the union L12 at one end and at the other end to a source of pressure. e3 are drilled holes connecting the chambers c2 and ,c3 with the elongated chamt ber alito provide air leaks. Y

The functioning of the apparatus above described is, as follows z-In the event of the pistonbeing moved to the left liquid will be forced via theI4 conduits ld? and d", the mushroom valve o? and the conduit d8 into the othery end of the chamberalf. If the piston is movedto the right liquidwill be forced via the conduit 7, the mushroom valve 0G, conduits (Z6, l5 and Z4 to the other end of the chamber au. In each case the passage of oil will be resisted by one or other ofthe springs 010 or 011 andthe air in one or other of the vessels cl2 and 013. By means ofthe pipe e giving access to the interior of the said' vessels by theconduits a8, a9 and als the pressure of air in such vessels may be varied and the resistance 'ofthe valves increased or diminished. t

The compression of the air may be by means of a pumpworked by the driver or compressing the air in conjunction with a` suitabl'eair vesselior vessels. For example, the variable compressionr maybe produced by a supply of air or oil or other fluid under pressure produced by a pump provided with ,anrelief valve or relief port in. manner well known, the spring of which relief valve or area of which relief portlis variable and controlled either-by a hand operated device or an automatic device which latter 4maybe a centrifugal device driven by the engine or transmission or other moving part. t

Referring to Figs. 6, 7 ,and 8, the reser-V voir g2, Fig. 6, is filled withoil which is pumped vby a gear pump g, into an air chamber g, the relief valve v71, being controlled either by the governor z' or lever lo. In an alternative arrangement shown"v in Fig. 7 a hand pump m is utilized to -pumpair into a reservoir n, the relief valve of which maybei controlled either by hand orby a centrifugal governor.

In another arrangement shown inFig. 8, a mechanically driven pump y', may be used instead of a hand pump. None of the devices illustrated in Figs. 6, 7, 8, or described with reference thereto constitute partsof the invention covered by the claims.

What I claim is y 1. A hydraulic shock damper comprising a cylinder, a member reciprocating therein adapted to form therewlth a compression air spring and means for varying the vpressure of the air therein.

2. A hydraulic shock ldamper for a mechanically propelled vehicle comprising a cylinder, a member reciprocating therein adaptedl to form therewith a compression chamber, a release for the esca-pe of liquid from the cornpression chamber, and a spring loaded valve controlling such release, a compressible air tight chamber forming an air spring, and automatic means for ,varying the pressure of the air consistently with the Vspeed of the road vehicle.

3. A hydraulic shock damper for a road vehicle propelled by the engine comprising a cylinder, a member reciprocating therein adapted to form therewith a compression chamber, a release forthe escape of liquid from the compression chamber, and a spring loaded valve controlling such release, an air spring loading said valve and automatic means for varying the pressure of the air consistently with the speed of the engine of the road Vehicle.

4. A hydraulic shock damper comprising a cylinder, a member reciprocating therein adapted to form therewith, a compression chamber, a release for the escape of liquid from the compression chamber, a spring and air loaded Valve controlling such release and means for varying the pressure of the air at will operable by the driver.

5. A hydraulic shock damper comprising' a cylinder, a member reciprocating therein adapted to form therewith a compression chamber, a release for the escape of liquid from the compression chamber, a mushroom Valve controlling such release loaded by av spring consisting of a cylindrical metal box with corrugatedexpandable sides, one end abutting against the head of the valve and the other iixed relatively to the cylinder and means for Varying the pressure of the air in the box.

6. A hydraulic shock damper as claimed in claim 5, a coil spring being contained in the said metal box reacting between the ends thereof.

In testimony whereof I have hereuntoA affixed my signature.

FREDERICK HENRY ROYCE. 

